I have noticed that the feces of one of my corns has been much thinner and almost a neon green color the past couple of weeks. I was going to try to get a picture of what it looked like in the aspen, but he was nice enough to let loose in the feeding bin this evening. Can anyone tell me what might be the problem? He hasn't eaten in a few weeks, but with the weather change it didn't really bother me until now.

To answer a few of the standard questions:

He is in a 32 qt tub in a rack
No new snakes in past 6 months
Back heat with a thermostat
Temp gun shows 83 in the back and 72 in the front
Aspen for the bedding
Feed frozen/thawed from RodentPro